The present invention relates to a semiconductor light-emitting device package and a method of manufacturing a semiconductor light-emitting device the package.
Semiconductor light-emitting device packages use a bottom portion of package or submount substrate as a heat sink and a package cap or window made of a transparent material to pass light therethrough. Specifically, in the above method, the heat sink and the window from which light is passed are formed independently.
FIGS. 1 and 2 of the accompanying drawings show, in cross-sectional form, examples of a package structure on which a semiconductor light-emitting device is mounted.
As shown in FIG. 1, a semiconductor light-emitting device package 8 comprises a substrate 1, a heat sink 2 mounted on the substrate 1, a laser diode 3 attached to the side surface of the heat sink 2, a cap attached to the substrate 1 for capping the laser diode 3 and the heat sink 2 and a transparent window 5 formed on the cap 4 to irradiate light L emitted from the laser diode 3. Reference numerals 6 denote terminal pins extended through the substrate 1. Reference numeral 7 denotes a metal thin interconnection for connecting an electrode of the laser diode 3 and the terminal pins 6.
A semiconductor light-emitting device package 10 shown in FIG. 2 is of the hybrid type. As shown in FIG. 2, the semiconductor light-emitting device package 10 comprises a package assembly 11, a semiconductor substrate 12 mounted on the bottom surface of the package assembly 11, a submount substrate 13 and a prism 14 mounted on the semiconductor substrate 12, a laser diode 15 attached to the submount substrate 13, and a transparent window 16 attached to the upper surface of the package assembly 11. In this semiconductor light-emitting device package 10, light L emitted from the laser diode 15 is reflected on the inclined surface of the prism 14 and is passed through the transparent window 16 to the outside. If the semiconductor light-emitting device package 10 is formed as an optical pickup, then reflected-back or returned light that has been reflected on a disk (not shown) is introduced into the prism 14 and received by a photodetector 17 formed on the surface of the semiconductor substrate 12 as shown by broken lines. In this case, the semiconductor substrate 12 and the submount substrate 13 act as a heat sink of the laser diode 15.
When the heat sink 2 and the side from which light L travels are formed on the different sides like the semiconductor light-emitting device 8 shown in FIG. 1, or the semiconductor light-emitting device package 10 is of the hybrid type as shown in FIG. 2, these packages 8 and 10 can be arranged by well-known methods.
FIG. 3 shows, in cross-sectional form, an example of a monolithic surface-emission light-emitting device wherein light is emitted on the surface of the device and a heat sink should be mounted on the same surface. As shown in FIG. 3, a laser diode 22 (reference numeral 22 generally represents an active layer) composed of a horizontal resonator is formed on a semiconductor substrate 21. A reflection surface 24 with an inclination of 45.degree. is opposed to a resonator end face 23A of resonator end faces 23A, 23B. Light L output from the resonator end face 23A is reflected on the reflection surface 24 and is emitted in the vertical direction. It becomes difficult to attach a heat sink to the above surface-emission light-emitting device.
In this case, there are restrictions arising from a device structure standpoint or device operation standpoint, such as the laser diode 22 being formed as a particularly high-efficiency type, the laser diode 22 being operated by a relatively low power or in a pulse operation fashion.
To solve the above-mentioned problem, an interconnection 26 formed on the surface of the laser diode 22 is increased in thickness by a proper method such as plating and this thick film interconnection 26 can serve as a heat sink. However, it is no so easy to form a metal thick film on an uneven device. Moreover, according to this technique, a satisfactory heat sink effect cannot always be achieved, i.e., heat is difficult to be transmitted to the outside.